Your search resulted in 61 documents. Displaying 25 entries per page.
Working Group I Sub-group 5 'Insects in dry wood'. Plan for data sheets
1982 - IRG/WP 1173
Comparison of cubic and plug samples for preparation and data assembly in permeability study
2000 - IRG/WP 00-20197
In order to determine if plug experimental samples (PES: 30 x 15 mm2 diameter) could be used for inspection of wood permeability characteristics, radial and longitudinal flow directions were prepared according to either PES or cubic experimental samples (CES: 100 x 20 x 20 mm3) from the sapwood zone of Sitka spruce and treated by tanalith-C according to full-cell process. Results from the two preparation techniques agreed in the test to determine the mean percentage of void volume filled by liquid both radially and longitudinally, while the preparation process (i.e. machining, sealing, etc.) of the experimental samples and the period of the data collection was quite longer in CES than that for PES in either flow direction.
Copper naphthenate performance: A new way to look at old data
2000 - IRG/WP 00-30215
Although copper naphthenate has over a 50-year test history, it is still considered as a "new" preservative in the United States when it is used for utility poles. It has also been extensively used in remedial treatments for poles and has considerable retail or over-the-counter sales. The test history includes a number of different tests and a rationale for evaluating this data and comparing the performance of copper naphthenate to other common pole preservatives is presented. Thus, the efficacy of copper naphthenate can be easily summarized.
C R McIntyre
Modelling of PCP migration in the environment: Feeding the models with laboratory data
1993 - IRG/WP 93-50001-08
In 1989, Hydro-Québec began a study program on pentachlorophenol (PCP) to ensure safe use of the product at all stages. One of the aspects of the study is the creation of a predictive system for evaluating the behavior of PCP and oil migration from wood poles to the environment. This system comprises four mathematical models for predicting PCP and oil migration in and on the surface of the pole, in soil and in groundwater, and for predicting runoff. Laboratory experiments aimed at quantifying and supplying the input for each model have been designed. A method of analyzing both PCP and oil in water. wood and soil has been developed. The radial and longitudinal distributions of PCP and oil concentrations have been established for several combinations of wood species and treatments. Laboratory setups and preliminary results are presented.
A Besner, P Tétreault, R Gilbert
Developing the technical guidance document on data requirements for biocidal products
1998 - IRG/WP 98-50101-02
Finland has been developing a discussion document for EC and the Member States concerning the specified data requirements for 23 biocidal product types, including wood preservatives, and their active substances. This data is required when applying for authorisation for a wood preservative according to the forthcoming Biocides Directive. The data requirements comprise of the core data set, which is common for all product types, and the product type specific additional data sets. The core data set has been outlined in the common position of Biocide Directive adopted by the EU Council and has only been complemented with some technical details. The data required in the additional data set is supplementary to the core data set and it takes into consideration the product type specific properties and direct and indirect human and environmental exposure. At the same time other guides have also been preparing: a guide for risk assessment of active substances by Sweden and a guide for risk assessment of biocidal products by UK. Close cooperation with these projects is an essential part of the preparatory work. After finalizing the draft discussion papers by the end of February 1998 the formal discussion on these will take place with EC and the Member States during 1998. The proposals on the data requirements will be circulated for comments to the EC, the Member States, industry and other interested parties. The final document will be addressed to the authorities and the applicants.
P Karvinen, E Nikunen
Boron treatments for the preservation of wood - A review of efficacy data for fungi and termites
1994 - IRG/WP 94-30037
Boron treatments have been used for many decades for protection of timber from biological attack and also as a fire retardant treatment. In recent years there has been an increased interest in boron treatments as an option for protection of structural timbers' e.g. timber framing used in termite risk areas. This paper reviews efficacy data for both fungi and termites relevant to this end-use.
J A Drysdale
Data sheet on woodboring insects. 1. Bostrychus capucinus (Linnaeus)
1979 - IRG/WP 193
Report on Sub-group 5 in Raleigh, 6 May 1980
1980 - IRG/WP 1123
On site test for indicative determination of leaching of components of preservatives from treated timber. Part 2: New data on CCA-C, CC and CCB treated timber
1994 - IRG/WP 94-50025
The 'on site test' was published at the IRG meeting in Cannes in February 1993 (IRG/WP 93-50001/12). Since this publication many on site tests were performed parallel to so-called shower tests. The correlation between the test results of the on site tests and the shower test has been established more clearly. For chromium the correlation between both tests is indistinctive of preservative formulation. For copper the correlation differs for CCA on one side and CC's and CCB's on the other side. In some cases the on site test does not correcty predict shower test results. The reasons for this phenomenon are discussed. It can be concluded that the on site test is a roughly indicative test for assessing the leaching of components of preservatives from treated timber. The correlation figures, however, are formulation dependent.
W J Homan
The use of chlorothalonil for protection against mold and sapstain fungi. Part 1: Laboratory evaluation
1989 - IRG/WP 3515
Laboratory screening of chlorothalonil alone and in combination with other fungicides was conducted against six mold and sapstain fungi. The most promising treatments appear to be chlorothalonil supplemented with CCA or copper-8-quinolinolate. Field tests have been implemented.
J A Micales, T L Highley, A L Richter
Risk assessment and the approval of wood preservatives in the United Kingdom
1995 - IRG/WP 95-50040-23
An approval system operates in the United Kingdom (UK) for the regulation of wood preservatives. The regulatory authority uses a risk assessment approach to evaluate how far the potential for harm to people and the environment from wood preservatives is likely to be realised in practise, and hence the controls required for products to be, used safely. The evaluation for approval purposes also takes into account the effectiveness of wood preservatives. A tiered approach is adopted to data requirements, and likely exposures are considered under the proposed conditions of use so that testing is minimised and controls are commensurate with risk.
R M Turner
Computerised data acquisitioning, handling and processing in wood preservation studies
1984 - IRG/WP 2218
The computerisation of data acquisitioning, handling and processing in weathering studies on wood treated with protective coatings is discussed. An integrated system comprising a data base, statistical package and a custom written graphical processor is explained. Two treatments are compared and the correctness of a mathematical weathering model is evaluated.
T Rypstra, K Vos
Data sheet on wood-boring insects: Ptilinus pectinicornis (Linnaeus)
1987 - IRG/WP 1334
S Cymorek, M-M Serment
Data requirements for wood preservatives in the EU Biocides Directive
2001 - IRG/WP 01-50166-08
Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products (the Biocidal Products Directive, BPD) lays down the requirements on data needed for authorisation of a biocidal product and approval of its active substance(s). The dossier must contain data needed for the proper risk assessment of the biocidal product. A detailed technical guidance document on data requirements for biocides has been produced to ensure the harmonised decision making according to the BPD. The purpose of the guidance is to give detailed testing strategies e.g. for toxicology, ecotoxicology and efficacy of different biocidal products and active substances, including wood preservatives. The data requirements for biocides are divided in two parts: the common core data set lists the studies which are always required, and the additional data set lists the studies which may be required in certain cases e.g. on basis of the results of the tests in the common core data set, and proposed uses and the potential exposure for a biocidal product. The common core data set contains a very comprehensive list of toxicological studies and, therefore, their additional data set is very limited. Instead, for ecotoxicological studies the common core data set is very limited, but the additional data set is very broad. Therefore, the guidance document on data requirement lists those additional ecotoxicological studies that are usually always required for certain biocidal product types - also for wood preservatives - in the application for approval. Waiving for some toxicological studies may be needed to minimise the need for animal testing and to reduce the costs of testing. The technical guidance document for data requirements gives some guidance on such a possibility on exemptions on the data requirements. The need for additional ecotoxicological testing depends on the product type and potential exposure for a product. In addition, the environmental risk found as a result from common core data set is the basic criterion when deciding testing strategy and the need for the additional ecotoxicological testing on e.g. adsorption, degradation and bioconcentration. Issues important for wood preservatives are data required on efficacy and on leaching from treated wood.
Questionnaire concerning assessment of test data from laboratory and field tests
1992 - IRG/WP 92-2418
During the WG II session in Harrogate, UK it was announced, that possibly a working-session on the assessment of test data and correlation between laboratory and field tests might be organised during next year's meeting in Orlando. For that pupose a questionnaire was prepared. The valuable comments and input of Prof. Thomas Nilsson from Sweden is hereby greatly acknowledged.
A R Valcke
The geographical distribution of the house longhorn beetle Hylotrupes bajulus (L) Serville (Col., Cerambycidae). An attempt at a cartographical compilation of existing data
1978 - IRG/WP 176
The larvae of the house longhorn beetle belong to the most economically important pests of softwood in service in most European countries and also in some areas overseas. I have reported earlier regarding the history, the question of where the pest originally came from, and concerning attacks in earlier and recent times (1968, 1970, 1974, 1976). In this report an attempt has been made to compile cartographically the currently existing data.
An in-ground natural durability field test of Australian timbers and exotic reference species. Part 5: Extensive data from a site where both decay and termites are active. Results from a full-replicated set of heartwood specimens from each of ten myrtaceous hardwoods after 18, 19 and 20 years' exposure - A discussion paper
1988 - IRG/WP 2324
Extensive data are presented on the decay situation, the termite situation and the decay-termite associations; all gathered from a fully-replicated set of heartwood specimens of 10 hardwood timbers after 18, 19 and 20 years' exposure in the ground at a single test site, i.e. a semi-arid steppe site. Sixteen tables are presented in addition to the one table providing the rating data; the latter representation of specimen condition being essentially all the data normally being recorded from field tests, whether these be of natural durability or preservative treated specimens. The authors give this "extra" data to show the type of information obtainable as a result of applying both mycological and entomological expertise to field assessments. Instead of discussing these results. the authors wish to generate some discussion by asking questions such as - is some of all of this information of value? - What additional/alternative information would interested scientists wish to see with respect to the most durable timbers in a test such as that examined in this report?
J D Thornton, G C Johnson, J W Creffield
The Biocidal Products Directive ( 98/8/EC ) - its consequences for the wood preservation industry
2001 - IRG/WP 01-50166-04
1. The Current Position This European Union Directive is one of the most technically complex pieces of legislation that has been developed by the European Commission (EC). Although the Directive was to have been implemented in the legislation of individual Member States of the EU by May 2000 progress has been slow. A number of Member States have yet to declare the Competent Authority who will handle their legislation. The body text of the Directive cannot stand-alone and is dependent on ancillary regulations and the development of technical guidance for both the Competent Authorities in the Member States and also industry to understand their roles in the whole process for the regulation of biocides and the biocidal products containing them. The process is far from complete in terms of a piece of workable legislation and this leaves not only industry but also the Competent Authorities with significant areas of uncertainty. This is potentially economically and socially damaging to the marketing and use of biocides and biocidal products. Because of this evolutionary process this paper can only be written in general terms as by the time the symposium takes place some significant changes to the position at the time of writing may have occurred. 2. Background The Biocidal Products Directive (98/8/EC), (BPD), is a directive which requires that biocides ( as active substances) are approved for use within the EU and the individual biocidal products containing these active substances are approved for use by the Competent Authority(s) of the Member State(s) in which it is intended to market the product. The product authorisation obtained in the first Member State should be mutually recognised by the other Member States in which application for authorisation to place the product on the market is sought. The Directive has to be seen in the context various other Directives, notably the Plant Protection Directive 91/414/EC). Biocidal products are grouped in the directive into twenty three "product types" and wood preservatives are Product Type 8. The intention of the directive is to harmonise the requirements for the placing of biocidal products and active ingredients on the market throughout the EU. EU wide use of so-called Common Principles are intended to be used to assess the dossiers in order to achieve a common approach and eliminate the current situation where individual Member States apply their own particular national approaches and criteria in the assessment and regulation of products . Annex IIA of the directive identifies the data requirements for the active substance and Annex II B for the biocidal product. There are additional data requirements identified in Annexes IIIA and IIIB for each product type reflecting potential for exposure to man and the environment. 3. Entry onto Annex I Any new active substance will require approval before it or any biocidal products including it can be placed on the market. The dossier to be submitted to the EC will have to include additional data and risk assessments for the product types (as defined in the BPD) in which it will be intended to be used. For those active substances that are accepted as being existing substances on the market before May 2000 (say in wood preservatives) these will be ranked and prioritised. This process is being defined in the so-called: Review Regulations. 4. An environmental directive There is no doubt that this Directive has a high environmental content in terms of the data and the associated risk assessments which are to be prepared. The protocols and the end points for some of these data requirements are still being developed. In general the EC considers that modelling exposure using human and environmental exposure scenarios covering the end use of the product is an acceptable approach . Data are required to enable these scenarios to be modelled and risk assessments made. It is necessary that regulators do not make decisions based on hazard assessment alone in the absence of fully worked out and agreed emission scenarios to define exposure levels which generate a realistic worst case risk assessment. Risk is a function of both hazard and exposure. A lot of work has been done in the development of Technical Notes for Guidance intended to help the regulator and the applicant in the submission and the interpretation of the data. Whilst it may be the case that the human toxicity data requirements still leave questions to be answered it is in the environmental aspects part of the regulatory process where there is still much work to be done. The Directive would seem to rely heavily on the development of Pass / Fail criteria in simulation tests. This is a big subject and of key importance to the risk assessment. 5. Wood preservatives ---- a test case Wood preservation has achieved a certain reputation. On the one hand it is said that a prime reason for the development of the Biocidal Products Directive arose from European problems in the regulation of the marketing and use of dangerous substances, notably wood preservatives. On the other hand because wood preservatives have been regulated by a number of Member States for many years it is believed they are well understood. The EC and the Member States also wanted to be seen to have achieved early success in the implementation of the Directive therefore the decision was taken to start, following failings with the speed of progress of the Plant Protection Products Directive, with a product type they knew all about i.e. wood preservatives. There is no doubt that there is a much greater understanding on the exposure scenarios, both human and environmental, for wood preservatives than many other product types. However, would it not have been better to have tackled some of the other product types where such an understanding is much less well developed? It is regrettable that the EC and Member States did not feel able to accept the results of an EC sponsored study (Haskoning report) on the assessment of risks for all the product types covered under the BPD. The results of this study clearly showed that wood preservatives did not constitute the most significant risk to man or the environment and in fact the risk was significantly greater for other product types. 6. Wood preservatives and the OECD Biocides Programme Another speaker will be covering this subject in more detail. Suffice it to say that because of the perception there was good knowledge about wood preservatives again they were selected as the pilot for an OECD project looking at environmental and human exposure assessment under the OECD Biocides Programme. The findings from two OECD Workshops actually demonstrated there was still much to be learnt about wood preservatives in order to refine the risk assessments to a state where they would be sufficient for the requirements of the BPD. This work is ongoing but it clearly demonstrates the problems that both the regulator and industry will have in the preparation and the assessment of the dossiers for both the active substances and the biocidal products. This is especially the case for other biocidal products that have not been subject to the same kind of regulation that wood preservatives have subjected to in the past. 7. Inorganic and organic biocides With current wood preservation technology there is still a dependence on inorganic chemicals such as copper (in conjunction with other biocides) or with chromium, as well as arsenic and boron for many end use applications. This is very much the case where a long term service life is a key factor in the use of treated wood for that end use. These substances are commodity chemicals and are also covered under the Existing Substances Regulations (EC) 1488/94. There is also work going on revising the Technical Notes for Guidance covering them . This includes a significant addition in the environmental risk assessment area. Efforts are being made to integrate and coordinate the requirements for both the BPD and the Existing Substances Regulations and OSPAR ( OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic). OSPAR refers to the Oslo Paris Convention. Whilst the BPD seems primarily aimed at the regulation of biocides based on organic chemicals wood preservative products may contain both inorganic and organic components. Indeed there are probably few wood preservative formulations on the market that contain only one active substance. This must have a significant impact on the way the dossiers are prepared for the active substance and the biocidal products and how they are assessed both at the EC and the Member State level. 8. Consequences of the BPD for the wood preservation industry Whilst this paper addresses the consequences for the wood preservation industry per se, it must not be overlooked that there may be implications for the fabricaÈors of articles made from treated timber. Some current wood preservative formulations may over a period of time be withdrawn from the market because the risks and costs of generating the data and the preparation of the dossier make the product economically unviable. The presence of large working volumes of wood preservative solutions at treatment plants requires realistic withdrawal periods to avoid the unnecessary disposal and associated environmental risk of products that have been used satisfactorily for many years. 9. Availability of active substances The structure of the industry has changed dramatically in the past few months and there is no doubt that other changes both within and outside the wood preservation industry itself are yet to happen. The original differentiation between formulator of wood preservatives and active substance suppliers to the wood preservation industry has become blurred. Some of the active substances used in wood preservation are used in other either other biocidal product types or in products regulated under another directive, e.g. Plant Protection Products Directive 91/414/EC. 10. Data protection This continues to be a key issue for industry and some companies may find it strategically or financially necessary not to support an active substance in a particular product type thus leaving that sector without being able to use the active substance. The coming months will start to reveal which active substances are likely to be supported, at least through the notification process. Formulators are therefore in a close dialogue with their suppliers to try to determine their intentions on whether or not they intend to support their active substance. Today's wood preservative formulations are largely multi active substance based. Product costs, efficacy spectra, niche marketing and other considerations have made this process inevitable. New wood preservative formulations take time to research and develop and the continuity of availability of a choice of active substances is of key importance. A lack of adequate return on investment necessary to sustain the development of new products could have a negative impact on innovation and the rate of introduction of new products. It is extremely unlikely that any new active substance will be solely developed for use in wood preservation. This would be an effect contrary to expectations of the EC. The situation with wood preservatives is complicated by the fact that treated wood is a construction product and comes under the scope of the Construction Products Directive (89/106/EEC) (CPD). Products under the scope of the CPD are required to meet certain so-called essential requirements and one of these is durability. Demonstration of compliance involves the extensive suite of CEN wood preservative efficacy tests. Even relatively small changes in formulations may require extensive re-testing under the EN 599 regime in some Member States. 11. Task Forces Companies are encouraged by the EC to enter into Task Forces in order to reduce the burden of testing on animals and also to reduce the number of dossiers to be reviewed for each active substance. Ideally, and understandably, the EC would like one dossier per active substance. Parts of the wood preservation industry have been co-operating in Task Forces and much practical experience has been gained. Even closer co-operation will be required and this will enable companies to pool experience and expertise and manage their financial exposure to potentially high regulatory costs by sharing them amongst a larger number of parties. 12. Financial aspects Industry will have to make some best guesses with respect to its investment programmes for supporting its portfolio of products. Formulators and active substance suppliers are likely to group into Task Forces in order to reduce their costs in terms of data generation and the fees likely to be charged at the EU and the Member State level for the assessment of the dossiers. The compilation of the dossiers requires specialist expertise to assist the industrial applicant(s). This is likely to cost in the order of £100,000 per active substance, not including the costs of generating any data. The Rapporteur State's costs for reviewing the dossier is also expected to be of the same order. Clearly these kinds of costs will impact on innovation. An adequate payback must be available to the company to justify this level of investment. 13. Will mutual recognition work? Member States are required to recognise the authorisation of the biocidal product placed on the market in the first Member State when subsequent applications are made to place the product on the market. This is a fundamental principle of the BPD, although there is concern that Member States continue to have enough flexibility to prevent this happening if there are particular concerns in that Member State. Industry very much hopes this will not be the case and that mutual recognition, a fundamental principle of the BPD, will work in practice. 14. Environmental aspects Biocidal products such as wood preservatives are generally applied in controlled situations and not over large areas. Consequently any emissions can be considered to be from discreet sources, such as treated timber or potentially from timber treatment plants. This is in contrast to plant protection products and some other biocidal products that are usually dispersed over a relatively large area. Because of this a lot of work is required to be done to re evaluate how the environmental aspects of biocidal products such as wood preservatives can be assessed in an objective manner. The criteria that define an emission and how the PEC (Predicted Environmental Concentration) for each environmental compartment is determined are critical. The wood preservation industry, through the EWPM (European Wood Preservative Manufacturers Group), has been working with institutes and other interested parties in a co-operation known as the EFG (Environment Focus Group) to progress the development of appropriate methodology. Data will be required for both primary and secondary exposure to treated timber. The protocols for this work are yet to be agreed. This work is being further progressed in the OECD together with input from CEN TC 38 WG27. This co-operation between the OECD and CEN is extremely significant in that it is, I believe, the first time such a co-operation has taken place in the development of an OECD Guideline. If one considers all of the end uses where treated timber may be found carrying out a risk assessment with few guidelines on how it should be done is a very uncertain process for both industry and the regulator. Reliance on so-called expert opinion may be inadequate. 15. Comparative assessment (the substitution principle) This is a process whereby the health safety and environmental properties of acti_u101 ? substances used in the same product type could be compared and those with the most undesirable properties would not be placed on Annex I. Consequently biocidal products containing them would have to be removed from the market. This process is embodied in the BPD but it was initially considered that it would only be applied in the event of problems arising with active substances or products containing them rather than being used as a screening tool early on in the review process for active substances. This area is still an uncertain one with Member States having different interpretations of this principle. It is unfortunate that the wood preservation industry could be used to test out this concept at a European level. The consequences of this principle could be further losses of active substances available to the wood preservative formulators. 16. Substances of concern The BPD is not only concerned with the active substances that are formulated into the biocidal product but also with so-called "substances of concern". These are defined as any substance, other than the active substance, which has the inherent capacity to cause an adverse effect on humans, animals or the environment and is present or is produced in a biocidal product in sufficient concentration to create such an effect. There are significant implications for the formulator of the biocidal product . The formulator may have to submit an extensive dossier containing toxicological and metabolic as well as ecological data on each of the substances of concern when seeking approval for the biocidal product. There may be classes of compounds that become unavailable to the formulator either because of the risks posed by the co-formulant or because the cost of generating data will be uneconomic. 17. The wood preservation Industry's view on the BPD Industry has supported the development of the BPD since its conception in 1989. It is still supportive it but believes that the degree of complexity is disproportionate to the level of risk when it comes to wood preservatives. After all wood preservatives have been regulated for a long time and in reality there have been few significant health safety and environmental problems associated with them. Industry believes there is no need to determine an absolute understanding about a biocide and its application but rather there is a need to determine the level of understanding that will enable characterisation so that a risk assessment can be made. The wood preservation industry has sought either directly or through representative bodies a pro-active and collaborative approach with the regulators although at times this appears to have encouraged inappropriate demands. The regulators have invariably responded positively to this however they may not always understand the burden in both time and resource in having made wood preservatives the test case. Industry hopes that its efforts to be pro-active will be recognised and will be dealt with equitably when considered before the other product types defined in the Biocidal Products Directive.
Wood Preservatives Science Issues: US EPA’s Perspective
2005 - IRG/WP 05-50224-2
The USEPA Office of Pesticide Programs (OPP), Antimicrobials Division (AD), regulates the use of chemicals registered as wood preservatives in the United States. An overview of the registration and re-registration process is presented. The wood preservatives data requirements include toxicological, human exposure, ecological, and environmental fate data. A detailed discussion of wood preservatives data requirements is presented. Currently, the three heavy duty wood preservatives (Pentachlorophenol, Chromated Copper Arsenate, and Creosote) are undergoing the re-registration process. This process is mandated by Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The re-registration process ensures that older pesticides meet contemporary safety standards and data requirements. The challenges of regulating the treated wood will be discussed.
Life-cycle assessement of treated wood: A view from the roa
1996 - IRG/WP 96-50078
Life Cycle Assessement (LCA) is being used increasingly as a tool to structure information on the environmental characteristics of material and processes. This paper is based on the experience gained from our LCA studies on treated wood products over the last 4 years. The comprehensive and logical examination af the information available on treated timber provided by LCA has allowed identification of gaps in our present state of knowledge. There is a large quantity of data available of preservatives and treated timber from past and present studies but, unfortunately, due to constrains in the original experimental design or recording data, much of it is of only limited use in environmental assessments. However, in many cases, only modest change in the design or parameter recorded would be needed to greatly increase their value for environmental impact assessments, such as LCA. A number of specific examples are used to illustrate these points in the paper, and possibilities for future developments in LCA are elaborated.
W Hillier, R J Murphy, D J Dickinson, J N B Bell
The mathematical study of test plot data
1987 - IRG/WP 2282
It has long been desirable to have a mathematical expression, which, by the insertion of statistically derived constants, would describe the behavior of test specimens in service. The philosophy of such expressions is briefly discussed, and the history of the concept is outlined. The modern approach to the problem dates from the graphical presentation of dosage-response and deterioration curves by Colley (1970). In 1972 Hartford devised the "Performance Index" giving a numerical parameter which could give statistically valid comparisons between preservatives in a given installation. A more potent tool is the "log-probability" method, which is now under consideration by AWPA P-6 as a standard. If "log score" is converted to probits x the relationship: x = a + b ln t + c ln R holds well for penta and creosote test specimens at log scores above 30, and tends to give conservative estimates of performance when early results are evaluated. With CCA, this is not true. Recent availability of 19-20 year test results on CCA stake and panel tests (Leach 1986) has permitted the evaluation of "modified probits" as the x in the above equation. Preliminary work shows promise: the CCA results are improved and low log scores can be used. Preliminary data are available on various CCA formulations and stake vs. panel tests.
W H Hartford
Some data on the activity of alternative fungicides for wood preservation
1985 - IRG/WP 3333
Data from laboratory tests against basidiomycete fungi are presented for 9 alternative fungicides in organic solvent formulations and also in water for one product. Results are compared with data for reference preservatives, tributyltin oxide, copper and zinc naphthenates and pentachlorophenol. Of special interest is the apparently better than additive effect of mixing tributyltin naphthenate and Xyligen B, and the promising performance of Armoblen 480, a novel organic solvent formulation of n-alkyl coco-derived quaternary ammonium compounds.
A F Bravery, J K Carey
Comparative study on leaching of CCA from treated timber: Modelling of emission data
1994 - IRG/WP 94-50027
Results of a comparative study on leaching of CCA from treated timber are reported. The study aims at investigating the applicability of prestandard leaching test methods for modelling purposes. Prestandards used are the European standard proposed by CEN/TC38/WG11 and NEN 7345 (Dutch prestandard for building materials). Parameters of study are type of fixation, wood species (pine - spruce), specimen dimensions and leaching pH. Due to the conditions of test, a higher level of metal emission is observed in the CEN procedure. Both methods show a similar time-related decrease in leaching flux, however. The CEN small wood block test using a dynamic stirring leaching system proves to be an accellerated version of the static NEN method in which pole sections are immersed in water over a long period of time. Steam fixation generally reduces the emitted quantities of chromium. When naturally fixated, the initial chromium flux exceeds the copper flux, while in accelerated (steam) fixation tests copper is leached out to a higher level. In most tests the initial arsenicum emission flux does not exceed one tenth of the respective copper flux. With regard to hazard assessment of CCA leaching from treated timber in surface waters, an emission model is worked out taking into account a number of controlable and verifiable parameters influencing the final environmental concentration. The PEC-formula used (predictable environmental concentration) is kept short and is based on time dependency of the emission data (curve fitting on experimental data) and substraction of calculated dilution factors.
G M F Van Eetvelde, M Stevens, L Van der Mijnsbrugge
How predictive are laboratory experiments for assessing the effects of chitin synthesis inhibitors (CSI) on field colonies of terrnites? - A comparison of laboratory and field data from Australian mound-building species of termit
1996 - IRG/WP 96-10143
A singular advantage of using mound building species of termite is their directly accessible nest. This allows evaluation of control methods by accurate assessment of the effects at the colony level. The mound building species Coptotermes acinaciformis (Froggatt) and Nasutitermes exitiosus (Hill) were used to test the CSI, hexaflumuron, in laboratory and field trials. Laboratory results showed that hexaflumuron was not repellent and it eliminated four gram groups of C. acinaciformis at a dose of 125 ppm and above within eight weeks. Groups of N. exitiosus were not affected by hexaflumuron: survival and wood consumption at doses of 0.25 to 1000 ppm were no different to those at zero ppm. Similar responses were obtained with the CSI triflumuron. These results would predict elimination of colonies for C. acinaciformis but not for N. exitiosus. However, field colonies of C. acinaciformis and also of N. exitiosus could be eradicated when exposed to hexaflumuron. Larvae and earlier stages of workers and nymphs died first, most likely during moulting, whereas the older foragers, which are the stages most often used in laboratory experiments, lived the longest. The latter was most pronounced in N. exitiosus. These results are the first to show the effects of a CSI on an entire colony, and demonstrated unambiguously the elimination of colonies after foragers had fed on bait matrix treated with hexaflumuron. Laboratory evaluations, using groups of older workers and soldiers, can fail to accurately predict the impact of these products at the level of most concern, the colony.
M Lenz, P V Gleeson, L R Miller, H M Abbey